T-Shirt Size
The T-Shirt Size is a relative estimation technique used in agile projects. Rather than using a number of planning pokers, here, Items are classified into t-shirt sizes: XS, S, M, L, XL, XXL…
T-Shirt Sizing is great when you need to arrive at only a rough estimate of size. Use it to filter out stories that are too big and should be broken down further. Or use it when you are picking from among projects that are already large.
Create and configure the custom field
To create and configure the T-Shirt size custom field, you must be logged in as a user with Jira administrator permissions.
Go to Apps → Manage your apps → Fields.
Click on Create custom field button on the right side of the screen.
Select T-Shirt Size and click Next.
Name and add a description to your field then click Next.
Select which icons you want to be available in issue view (all by default), select between two available View options, select a desired color and click Next.
Associate the field to the appropriate screens and click Create. You must associate a field to a screen before it will be displayed.
To restrict editing access for the Multilevel Select Picker, the Edit Permissions tab is used. Specific users, user groups, and Jira roles can be defined to have editing permissions for the custom field. If editing access is intended for all users, the field should be left empty.
Please note that the create screen has a separate toggle that allows defining whether users without edit permissions can create values in create screens.